Help me settle something - Mio commercial

I'm sure most of you have seen this commercial, but for those who haven't it's right here

Now throughout the commercial, the characters change appearance, and they even change the actual actors. But the voices remain constant throughout the commercial. But it seems that the man sitting down changes voice actors when he appears as the black guy. Your thoughts? Is it the same voice actor or a different one? And if it's different, why would they only change voices when he appears as a black guy?